Bruce Hawkins

Governing Principles and Concepts of Lean Maintenance

This chapter deals with the governing principles and concepts of lean maintenance. Governing principles are the applied standards for defining policy, direction and objectives for the lean enterprise. There are three governing principles behind lean manufacturing: waste elimination, focus on customer, and quality generated at the source. Waste elimination actively seeks to identify and eliminate waste, which is anything that does not add value for the customer. The maintenance operation is focused on what the customer values, which, in general, are related to low cost, product quality and reliability, timeliness and demand for a product/function. The quality of maintenance activities translates to correctly performing the right maintenance at the right time and the first time. Maintenance tasks are performed using the correct parts, materials and consumables in the correct quantity. Successful maintenance functions are built upon governing principles and a layer of support concepts of how the lean maintenance operation functions. The chapter presents ten concept statements, which are considered essential for support of the lean maintenance operation.

Historical View of Maintenance

This chapter provides a historical view of maintenance. Since the creation of Earth, the practice of maintenance has been there for an infinitesimal amount of time. There are still many lessons to be learnt on the quest for perfection in the practice of maintenance. Even though the first tools were used by hominids, maintenance was slow to evolve. It was not until the coming of the metal ages and following the evolution of the wheel that any true form of maintenance really became widespread. Various timelines trace the evolution of maintenance correlated to the evolution of Earth, human evolution, and the evolution of technology. The geological time line represents the time from the formation of Earth through the pre-Cambrian era and into the Paleozoic era. The hominid time line represents the evolving human forms from the earliest species of Australopithecus, during the time of the ancient Stone Age, to the more modern forms of the new stone age of Homo erectus and Homo sapiens. The industrial age break down the technological evolution of tools, machines, and manufacturing and maintenance practices. The birth of real maintenance took place with industrial revolution. The second event to have a profound influence on maintenance operations was the First World War.

Tips, Tricks and Avoiding Pitfalls

This chapter presents a smattering of lessons learned from practitioners of the fine arts of maintenance planning and scheduling. Although it is human nature to at least try to avoid making errors, especially in ones chosen vocation, they are bound to make their way into your operation, often at the most inopportune time possible. This chapter also contains many tips and tricks of the trade garnered from, sometimes, unexpected successes. Maintenance trades tend to mistrust maintenance planners. Unless planners can overcome this and win the trust of the maintenance trades, theirs will be a long and arduous journey toward having their work plans carried out effectively. The chapter further presents practices that can enhance the work planning function and additional general considerations to keep in mind while setting up the plants planning function and executing the planning function. It also presents methods for performing scheduling and general considerations to keep in mind while setting up scheduling function as well as when executing the scheduling function.

The Plant/Facility Lean Environment

This chapter focuses on maintenance planning and maintenance scheduling as performed in the lean environment. It deals with lean manufacturing. Lean Manufacturing is the practice of eliminating waste in every area of production, including customer relations, product design, supplier networks, production flow, maintenance, engineering, quality assurance, and factory management. Its goal is to utilize less human effort, less inventory, and less time to respond to customer demand, less time to develop products, and less space to produce top quality products in the most efficient and economical manner. The complexity of lean manufacturing is in identifying waste and then eliminating it. The first step in identifying waste in any process is to define the current state of the process, which is done by beginning at the end of the process and mapping each step of the process by following it in reverse. In the lean environment, the most commonly used method for mapping the current state of a process is referred to as value stream mapping. The chapter further discusses total productive maintenance (TPM). TPM objectives include the elimination of all accidents, defects and breakdowns. TPM addresses the entire production system life cycle and builds a solid, shop floor-based system to prevent all losses.

Origins of the Maintenance Planner

This chapter discusses the origin of maintenance planner. The origin of planner/schedulers can vary significantly depending on how planning maintenance and scheduling maintenance are defined. Earlier, it was pointed out that pre- and post-flight checks on military and commercial aircraft had their origins in First World War. The aircraft branches of the military continued to lead the evolving practice of maintenance with their adoption, in the 1930s, of standardized, periodic flight-time based inspections of airframes and aircraft engines. Each increasing hourly-based inspection involved an increasingly detailed level-of-inspection, ultimately arriving at complete disassembly for individual part inspection and replacement. These flight-time based inspections brought the requirement for skilled planning and scheduling. The flight-hour based inspections required some planning skill to keep airframe and engine inspections synchronized and even more skill at maintaining staggered off-line schedules for squadron aircraft. In todays manufacturing environment, the requirements for maintenance planners have become much broader in scope and more complex in execution. There is a fundamental process for maintenance planning and scheduling, and depending on the unique variables at every plant or facility, additional process requirements may be assigned to the planning and scheduling function.

Metrics: Measuring Planning and Scheduling Performance

This chapter discusses planning measurement and scheduling performance or metrics. A performance measure, or metric, is simply the measurement of a parameter of interest, such as labor hours scheduled. The combinations of several metrics yield indicators serve to highlight some condition or highlight a question that needs answering, such as “Completed Hours / Scheduled Hours.” Key performance indicators (KPIs) combine several metrics and indicators to yield an assessment of critical or key processes. KPIs can be created in a hierarchical and interlinked fashion that allows management to pinpoint the root causes of system failures. To determine maintenance planning and scheduling strengths and weaknesses, KPIs should be broken down into those areas for which the performance levels are needed to be known. Depending on KPI values, they are classified as either leading or lagging indicators. Leading indicators are indicators that measure performance before a problem arises. Lagging indicators yield reliability issues, which will result in capacity issues.

Performing the Planning Function

This chapter discusses maintenance planning. Maintenance planning is the advance preparation of selected jobs so that they can be executed in an efficient and effective manner when the job is performed at some future date. It is a process of detailed analysis to first determine and then describe the work to be performed, by task sequence and methodology. It includes developing an estimate of total cost and encompasses essential preparatory, post maintenance, and restart efforts of both operations and maintenance. The maintenance planner must have the requisite personal skills as well as professional skills derived from experience and through, comprehensive training to execute professional maintenance planning. The maintenance planner initiates job planning based on work orders received and the coded information on the work order. The coded information includes work type, work category, and work classification, but initially, the primary interest of the planner is focused on the priority that has been indicated for the work.

Special Case: Maintenance Planning and Scheduling for Maintenance Outages — The Plant Shutdown

This chapter discusses maintenance planning and scheduling for maintenance outages, and plant shutdown. The majority of preventive and planned maintenance work is performed while the manufacturing plant is in operation. Major maintenance work that is required at some point cannot be performed while the plant is operating. Entire production lines need to be shut down for major equipment overhaul or even replacement. This shutdown is referred to as a maintenance outage. The maintenance outage involves a total plant shutdown. It is less expensive to simultaneously shutdown all plant operations to perform major maintenance work on all plant equipment needing it than it is to conduct more frequent shutdowns in separate areas of the plant. This is referred to as a plant maintenance shutdown or plant shutdown. Plant shutdowns can be complex, not only due to the nature of the work to be performed, but also because of the pressure to try to force as much work as possible into as short a shutdown period as possible. As the volume of work increases, the complexity of the maintenance outage increases, rendering the shutdown even more costly and more difficult to manage.

Performing the Maintenance Scheduling Function

This chapter discusses how the maintenance scheduling function is performed. The scheduling of maintenance work, including associated coordination with the equipment custodian, is the process by which designated resources and resource skill levels required to complete specific jobs are allocated. The allocated resources are further coordinated and synchronized to be at the proper place at a designated time, with necessary access, so that work can be started and proceed to completion with minimal delay, within the intended time frame and in accordance with predetermined priorities and budgets. On the start up of any new maintenance management implementation, scheduling should be viewed as the point element of the program. Scheduling necessitates early, positive participation of the users of maintenance service and yields the earliest results. The scope of maintenance scheduling encompasses the allocation and coordination of the resources required for specific jobs. It also includes the determination of when jobs get done and which resources can best be applied to their performance.

Planning and Scheduling Fundamentals—Self-Test

The aim of this chapter is to determine the comprehension and retention of the material in chapters 1 through 10, and to provide a review and summary of that same material. The chapter includes a self-test question and answer section related to planning and scheduling fundamentals. This self-test is the most effective method for both the comprehension of the material in this text and the long-term retention of the material. Work exercises in this section are basically small-scale samples of the types of activities that maintenance planners and schedulers will be performing on the job.